Robert Johnson, the co-founder of LetsRun.com, said the hypothetical question has been debated by runners for years on his website. He said he's "very confident" that Bolt wouldn't even be able to break the five-minute mark:

"If that was the over/under, I'd mortgage my nonexistent house to try to bet up to six figures he was over that," Johnson said. "He's a total fast-twitch-muscle-fibre guy. To expect Bolt to be good at the mile simply because he is the world's greatest sprinter would be like expecting a great three-hundred-and-twenty-pound N.F.L. offensive lineman to be good at playing running back simply because he's a great football player. It's ludicrous."
Robert Johnson, Co-founder, LetsRun.com

Even so, we're not trying to race Usain Bolt in the mile anytime soon.